Method of treating metal containing hydrocarbon oils



METHOD OF TREATING METAL CONTAINING HYDROCARBON OILS Frank A. Mirabile,Belleville, N.'J., assignor to The M. W1 Kellogg Company, Jersey City,NJ., a corporation of- Delaware No Drawing. Filed May 27, 1958, Ser. No.738,021

11 Claims. 01. 208-284) The present invention relates to demetallizationprocesses. In one of its aspects, the invention relates toa. process forthe demetallization of hydrocarbon oils. More particularly, in thisaspect, the invention relates to an improved process for the removal ofmetal contamibeen found that this condition is largely due to thedeposition of metallic contaminants, present in the feed,

upon the catalytic material. These metallic contaminants which areharmful to catalytic activity have been found to comprise unfilterablemetals or metallic compounds, particularly those of nickel, vanadium,ironand copper. In addition, it has also been found that organic metalsalts are present in these hydrocarbon oils which may have been formedby the corrosion of refinery equipment by organic acids present in thefeed. These metallic contaminants tend to accumulate upon the catalyst,and their removal is extremely difficult because of the relatively smallamounts of the metal contaminants present in the feed, these amountsbeing in the order of from to 100 parts per million. 7

Various methods have heretofore been suggested for removing orloweringthe metallic contaminant-content of hydrocarbon oils or feedstocks, to reduce catalyst contamination. Among these methods are thosewhich embody treating such feeds with strong mineral acids to react withthe metal contaminants, and subsequently separating the resulting metalsalts by conventional methods. Such procedures, however, have been foundto result in hydrocarbon decomposition; and in instances whereoxygenated organic compounds may also be present in the aforementionedfeeds, there is a tendency for these compounds to react with the acidtreating agent, thus effecting their subsequent recovery in a state ofunchanged composition. Other proposed methods embody treating theaforementioned metal-containing hydrocarbon oils with varyingconcentrations of alkali-treating agents. Such methods have alsobeenfound to be undesirable, inasmuch as they are limited to only a partialrecovery of the metal contaminants present. This result is encounteredwhere a sufficient amount of alkalitreating agent isused to neutralizethe free organic acids which may be present in such metal-containinghydrocarbon mixtures, and it is desired to remove the metal as its oxideor hydroxide. Where such quantities of alkali-treating agent areemployed, there is a tendency of the alkali to promotehndesirableside-reactions, such as the condensation and/ or polymerization ofcarbonyl compounds (e.g., aldehydes or ketones), unsaturated products,and materials containing polyfunctional groups. Such action is more aptto occur in the presence of alkali-treating agents ateint l atented July12, 1960 than in the presence of mineral acids, when the latter areemployed as treating agents. Still other methods for removing dissolvedmetal impurities in admixture with hydrocarbons have been unsuccessfullyattempted in the past. For example, distillation by conventional methodshas proved undesirable because of hydrocarbon decomposition caused bythe application of heat. Similarly, molecular distillation has beenshown to be ineifective in separating metallic impurities from'theaforementioned hydrocarbon oils.

Itis, therefore, an objectof the present invention to provide animproved method for the demet-allization of hydrocarbon oils. 1

Another object .of the invention is to provide an proved method for theremoval of metal contaminants present in hydrocarbon oils, such as areemployed in catalytic cracking operations.

Still another object of the invention is to provide an improved,efiicient and economical method for substantially complete removal ofmetal contaminants present in hydrocarbon oils, such as are employed incatalytic cracking operations.

Various other objects and advantages inherent in the invention willbecome apparent from the following more detailed disclosure anddescription.

In accordance with the improved process of the present invention, asmore fully hereinafter described, metal contaminants, present in varyingconcentrations,

may be substantially completely removed from the aforementionedhydrocarbon oils by treating these oils with strong halogenating agentscontaining chlorine or bromine substitution, to convert these metalcontaminants to their metallic halides. The metallic halides thusproduced are thereafter readily separated from the hydrocarbon oil sothat the metal-free hydrocarbon mixtures are obtained. The halogenatingagent which is employed for the removal of the aforementioned metalcontaminants, is, as indicated above, one in which the halogens areselected from the group consisting of chlorine and bromine. Preferredbalogenating agents comprise sulfuryl chloride, sodium hypochlorite,chlorine, bromine or N-bromosuccimide.

The treatment of the aforementioned hydrocarbon oils, such as, forexample, employed in catalytic cracking operations, is carried out withthe halogenating agent in either a batch-wise or continuous operation.In a given treatment, it is found that the mole ratio of thehalogenating agent to the quantity of metallic contaminants present inthe feed stock treated, in general, may vary from about 1 to about 5moles of chlorinating agent to the quantity of metal contaminantspresent. Greater quantities of the chlorinating agent with relationshipto the quantity of metal contaminants present may, however, be employedin the process of the invention, but such increased quantities are notdesirable since they do not result in any improvement in metal removal,from an economic standpoint. Preferably, mole ratios of halogenatingagent to metal contaminants present ranging from about 1:1 to 3:1 arepreferred, since such ratios result in obtaining optimum (i.e.,substantially complete metal removal) conditions employing minimumquantities of the halogenating agent.

It hasbeen found, in accordance with the process of the presentinvention, that the rate ofchlorination or bromination is favored by anincrease in temperature. However, if the temperature employed isexcessive, too high a rate of halogenation takes place and too large aquantity of the halogenating agent is consumed. This maybe followed byhalogenation of the hydrocarbon 3 components themselves. entthepossibility of hydrocarbon decomposition where the temperature employedis exceedingly high. In general, temperatures between about 60 F. andabout 300 F. are satisfactorily employed. While temperatures below 60 F.may also be employed, it is nevertheless found that the rate of reactionproceeds too slowly so that economic and efficient metal removal is notobtain'ed. Where elevated temperatures are desired to be emloyed, inorder to hasten the rate of metal removal, ranges between about 200 F.and about 300 F. are satisfactorily employed. In general operation,however, a temperature between about 60F. and about 200 F. is normallyutilized. Y

employed in carrying out the halogenation reaction, it

is found that pressures between about 1 atmosphere and about atmospheresare satisfactorily employed. In instances where the halogenating agentis employed in a liquid state and the operation is carried out withinthe uppermost limits of the temperature range (e.g., between about 200F. and about 300 F.), it is preferred to carry out the reaction atpressures which are significantly :above atmospheric pressure in. orderto maintain the halogenating agent in a liquid phase condition.

As previously indicated, the metal contaminants which are effectivelyremoved, in accordance with the process of the present invention,comprise such metals as nickel, vanadium, iron, copper and theircompounds. Employing nickel oxide as representative of metalcontaminants present in the aforementioned hydrocarbon oils or petroleumfeed stocks, the complete removal of this metal from the feed, employingsulfuryl chloride as representative of the aforementioned halogenatingagent, may be illustrated by the following equation:

Similar reactions take place when any of the other metal contaminantsare present in the feed, such as vanadium, iron, copper, etc., employingeither sulfuryl chloride or any other of the other aforementionedhalogenating agents.

As indicated above, the metal contaminants removed from the hydrocarbonoils, in accordance with the present invention, may be present either inthe form of the ele- Qmental free metal or in the form of metalliccompounds. In this respect, it has been found that in ceitain feedmaterials, particularly heavier crude oil fractions containingrelatively large quantities of metal contaminants, such as nickel,vanadium, iron, copper or mixtures thereof, these metals are present inthe form of metal porphyrins. lThese metal porphyrins, when present infeeds employed in hydrocarbon conversion processes, e.g., catalyticcrackling operations, tend to deposit on the catalyst, as previouslyindicated, during cracking. With the above in mind, the effect of anumber of halogenating agents for effecting demetallization of theaforementioned hydrohalogenating agents upon solutions containing nickeletio- In each run a 10 cc. solution of nickel porphyrin. etioporphyrin,comprising 12.1 p.p.m. Ni in pyridine, was treated with the halogenatingagent for a period of :16 .hours. The data in the table disclosesthequantities :of halogenating agent employed and the degree of metal.contaminant finally removed after the 16 hour period.

In addition, there is also pres- Table I Mg. of Final Percent RunHalogenating Agent Halogen- Temp. p.p.m. Ni N o. atlug Ni removed Agentl 1 sulfurylchloride {i312 5833 .5: 8 i88:8 2 sodium hypochlorite. 50. 0reflux. 0 100. 0 chlorine 1 room...- 0 100. 0 50.0 reflux. 0 V 100. 022.0 reflux- 0 100. 0 {30. 9 room..-. 8 34. 0 30. 9 reflux. 8 34. 0 1{24. 9 room... 9 26. 8 24. 9 reflux. 9 26. 8 {20. 9 room I8. 6 29. 0 20.9 reflux. 8. 6 29. 0 50.0 reflux. 5. 3 56.0 62. 0 reflux. 12. 1 0

1 Room temperature=68 F. 9 Reflux temperature=reflux temperature ofpyridine, viz., 221 F.

From Table I above, it will be noted that the halogenating agents of thepresent invention, viz., sulfuryl chloride, sodium hypochlorite,chlorine, bromine and N- bromo succinimide, were extremely effective incomplete removal of the nickel contaminant present, as evidenced fromthe data in runs 1 through 5. On the other hand, it will be noted thatother halogenating agents were not effective in the total removal ofnickel contaminants, as is evidenced from runs 6 through 10 in thetable.

The following table illustrates the effect of various halogenatingagents upon solutions containing vanadyl etioporphyrin. In each run, a10 cc. solution of vanadyl etioporphyrin, comprising 12.8 p.p.m.vanadium in benzene, was treated with the halogenating agent for aperiod of 15 hours. The data in the table discloses the quantities ofhalogenating agent employed and the de- Table II Mg. of Final PercentRun Halogenatlng Agent Halo en- Temp, p.p.m. V N o. ating F. V removedAgent sulfuryl chloride 50.0 68 0 100.0 N-brornosuccinimide 20.0 81 0100.0 HF 50.0 81 12.8 0 HI 50.0 81 12.3 4. 0 HBr 50.0 81 10. 6 '17. 0

From the data disclosed in Tables I and II, it will be noted that thehalogenating agents of the present invention, viz., sulfuryl chloride,.sodium hypochlorite, chlorine, bromine and N-bromosuccinimide areoutstandingly effective in obtaining substantially complete metalremoval, 'by converting the aforementioned metal contaminants to theirmetallic halides. On the other hand, it will also be noted that otherhalogenating agents are not effective in obtaining a total metal removalas shown in the aforementioned runs. With reference to Table II,

' it will be noted therefore, that while the aforementionedV(etioporphyrin) +5SO Cl V01 +etioporphyrin)Cl +5SO As indicated above,the present invention is directed to an improved process for the removalof metal contaminants present in hydrocarbon oils, and has particularapplicability to the treatment of hydrocarbon oils employed in catalyticcracking operations. However,

. while the invention has been described as having a particularapplicability to the separation of metal impurities from hydrocarbonmixtures obtained from such sources, it should be noted that the processof the invention is not necessarily restricted to efiect the desiredmetal separation from such hydrocarbon mixtures. The process of thepresent invention may also be successfully applied to the separation ofmetal impurities from any mixtures of hydrocarbon oils without regard tothe source from which these mixtures may have been derived. It shouldalso be noted that while a particular embodiment of the process of thisinvention has been described for the purposes of illustration, variousmodifications and adaptations thereof, which will be obvious to thoseskilled in the art may also be made within the spirit of the invention.

I claim:

1. A method for treating a hydrocarbon oil containing metal contaminantswhich comprises contacting said oil with a halogenating agent selectedfrom the group consisting of sodium hypochlorite and N-bromosuccinimideto convert said metal contaminants to their metallic halides.

2. The process of claim 1 in which the halogenating agent comprisessodium hypochlorite.

3. The process of claim 1 in which the halogenating agent comprisesN-bromosuccinimide.

4. A method for treating a hydrocarbon oil containing metal contaminantswhich comprises contacting said oil with a halogenating agent selectedfrom the group consisting of sodium hypochlorite and N-bromosuccinimideat a temperature between about 60 F. and about 300 F. to convert saidmetal contaminants to their metallic halides.

5. A method for treating a hydrocarbon oil containing metal contaminantswhich comprises contacting said oil with a halogenating agent selectedfrom the group consisting of sodium hypochlorite and N-bromosuccinimideat a temperature between about 200 F. and about 300 F. to convert saidmetal contaminants to their metallic halides. I

6. A method for treating a hydrocarbon oil containing metal contaminantswhich comprises contacting said oil with a halogenating agent selectedfrom the group consisting of sodium hypochlorite and N-bromosuccinimideat a temperature between about F. and about 300 F. and at a pressurefrom about 1 atmosphere to about 10 atmospheres to convert said metalcontaminants to their metallic halides.

7. A method for treating a hydrocarbon oil containing metal contaminantswhich comprises contacting said oil with a halogenating agent selectedfrom the group consisting of sodium hypochlorite and N-bromosuccinimideat a temperature between about 200 F. and about 300 F. and at a pressurefrom about 1 atmosphere to about 10 atmospheres to convert said metalcontaminants to their metallic halides.

8. A method for treating a hydrocarbon oil containing .metalcontaminants which comprises contacting said oil with a halogenatingagent selected from the group consisting of sodium hypochlorite andN-bromosuccinimide in an agentzmetal mole ratio between about 1 andabout 5 and at a temperature between about 60 F. and about 300 F. toconvert said metal contaminants to their metallic halides.

9. A method for treating a hydrocarbon oil containing metal contaminantswhich comprises contacting said oil with a halogenating agent selectedfrom the group consisting of sodium hypochlorite and N-bromosuccinimidein an agentzmetal mole ratio between about 1 and about 5 and at atemperature between about 200 F. and about 300 F. to convert said metalcontaminants to their metallic halides.

10. The process of claim 6 in which the halogenating agent comprisessodium hypochlorite.

11. The process of claim 6 in which the halogenating agent comprisesN-bromosuccinimide.

References Cited in the file of this patent UNITED STATES PATENTS

1. A METHOD FOR TREATING A HYDROCARBON OIL CONTAINING METAL CONTAMINANTSWHICH COMPRISES CONTACTING SAID OIL WITH A HALOGENATING AGENT SELECTEDFROM THE GROUP CONSISTING OF SODIUM HYPOCHLORITE AND N-BROMOSUCCINIMIDETO CONVERT SAID METAL CONTAMINANTS TO THEIR METALLIC HALIDES.